the thing most of these threads skip: oral NAD+ has pretty poor bioavailability. it doesn’t cross cell membranes well as an intact molecule, so your gut breaks it down before it gets where you’d want it. imo NMN (and NR) are precursors that convert to NAD+ intracellularly, which is why they’ve gotten more research attention as a delivery mechanism. so “which works better” kind of depends on what you mean. taking NAD+ directly isn’t necessarily taking the shortcut you’d think. what the evidence actually says (as of now)
- NMN and NR both raise blood NAD+ levels in humans. that part is pretty consistent across trials. - whether raised NAD+ levels translate to subjective energy or focus improvements is way less clear. most trials aren’t designed to measure that. - dose matters a lot. 250mg NMN vs 1000mg NMN are not equivalent. a lot of people try the lower dose, feel nothing, and conclude it doesn’t work. the part nobody talks about: if your energy crash is metabolic (insulin resistance, poor glucose regulation) rather than mitochondrial aging, NAD+ precursors are probably not the lever you want. they’re not glucose disposal agents. i’ve seen people with undiagnosed IR spend money on NMN when their fasting insulin was just quietly terrible. mid-day crash at 30 with a desk job warrants a fasting insulin and glucose before you go down the supplement rabbit hole, imo.